a

libc/fmtquote.c

@@ -0,0 +1,247 @@
+#include <u.h>
+#include <libc.h>
+#include "fmtdef.h"
+
+/*
+ * How many bytes of output UTF will be produced by quoting (if necessary) this string?
+ * How many runes? How much of the input will be consumed?
+ * The parameter q is filled in by _quotesetup.
+ * The string may be UTF or Runes (s or r).
+ * Return count does not include NUL.
+ * Terminate the scan at the first of:
+ *	NUL in input
+ *	count exceeded in input
+ *	count exceeded on output
+ * *ninp is set to number of input bytes accepted.
+ * nin may be <0 initially, to avoid checking input by count.
+ */
+void
+_quotesetup(char *s, Rune *r, int nin, int nout, Quoteinfo *q, int sharp, int runesout)
+{
+	int w;
+	Rune c;
+
+	q->quoted = 0;
+	q->nbytesout = 0;
+	q->nrunesout = 0;
+	q->nbytesin = 0;
+	q->nrunesin = 0;
+	if(sharp || nin==0 || (s && *s=='\0') || (r && *r=='\0')){
+		if(nout < 2)
+			return;
+		q->quoted = 1;
+		q->nbytesout = 2;
+		q->nrunesout = 2;
+	}
+	for(; nin!=0; nin-=w){
+		if(s)
+			w = chartorune(&c, s);
+		else{
+			c = *r;
+			w = runelen(c);
+		}
+
+		if(c == '\0')
+			break;
+		if(runesout){
+			if(q->nrunesout+1 > nout)
+				break;
+		}else{
+			if(q->nbytesout+w > nout)
+				break;
+		}
+
+		if((c <= L' ') || (c == L'\'') || (doquote!=nil && doquote(c))){
+			if(!q->quoted){
+				if(runesout){
+					if(1+q->nrunesout+1+1 > nout)	/* no room for quotes */
+						break;
+				}else{
+					if(1+q->nbytesout+w+1 > nout)	/* no room for quotes */
+						break;
+				}
+				q->nrunesout += 2;	/* include quotes */
+				q->nbytesout += 2;	/* include quotes */
+				q->quoted = 1;
+			}
+			if(c == '\'')	{
+				if(runesout){
+					if(1+q->nrunesout+1 > nout)	/* no room for quotes */
+						break;
+				}else{
+					if(1+q->nbytesout+w > nout)	/* no room for quotes */
+						break;
+				}
+				q->nbytesout++;
+				q->nrunesout++;	/* quotes reproduce as two characters */
+			}
+		}
+
+		/* advance input */
+		if(s)
+			s += w;
+		else
+			r++;
+		q->nbytesin += w;
+		q->nrunesin++;
+
+		/* advance output */
+		q->nbytesout += w;
+		q->nrunesout++;
+	}
+}
+
+static int
+qstrfmt(char *sin, Rune *rin, Quoteinfo *q, Fmt *f)
+{
+	Rune r, *rm, *rme;
+	char *t, *s, *m, *me;
+	Rune *rt, *rs;
+	ulong fl;
+	int nc, w;
+
+	m = sin;
+	me = m + q->nbytesin;
+	rm = rin;
+	rme = rm + q->nrunesin;
+
+	w = f->width;
+	fl = f->flags;
+	if(f->runes){
+		if(!(fl & FmtLeft) && _rfmtpad(f, w - q->nrunesout) < 0)
+			return -1;
+	}else{
+		if(!(fl & FmtLeft) && _fmtpad(f, w - q->nbytesout) < 0)
+			return -1;
+	}
+	t = f->to;
+	s = f->stop;
+	rt = f->to;
+	rs = f->stop;
+	if(f->runes)
+		FMTRCHAR(f, rt, rs, '\'');
+	else
+		FMTRUNE(f, t, s, '\'');
+	for(nc = q->nrunesin; nc > 0; nc--){
+		if(sin){
+			r = *(uchar*)m;
+			if(r < Runeself)
+				m++;
+			else if((me - m) >= UTFmax || fullrune(m, me-m))
+				m += chartorune(&r, m);
+			else
+				break;
+		}else{
+			if(rm >= rme)
+				break;
+			r = *(uchar*)rm++;
+		}
+		if(f->runes){
+			FMTRCHAR(f, rt, rs, r);
+			if(r == '\'')
+				FMTRCHAR(f, rt, rs, r);
+		}else{
+			FMTRUNE(f, t, s, r);
+			if(r == '\'')
+				FMTRUNE(f, t, s, r);
+		}
+	}
+
+	if(f->runes){
+		FMTRCHAR(f, rt, rs, '\'');
+		USED(rs);
+		f->nfmt += rt - (Rune *)f->to;
+		f->to = rt;
+		if(fl & FmtLeft && _rfmtpad(f, w - q->nrunesout) < 0)
+			return -1;
+	}else{
+		FMTRUNE(f, t, s, '\'');
+		USED(s);
+		f->nfmt += t - (char *)f->to;
+		f->to = t;
+		if(fl & FmtLeft && _fmtpad(f, w - q->nbytesout) < 0)
+			return -1;
+	}
+	return 0;
+}
+
+int
+_quotestrfmt(int runesin, Fmt *f)
+{
+	int outlen;
+	Rune *r;
+	char *s;
+	Quoteinfo q;
+
+	f->flags &= ~FmtPrec;	/* ignored for %q %Q, so disable for %s %S in easy case */
+	if(runesin){
+		r = va_arg(f->args, Rune *);
+		s = nil;
+	}else{
+		s = va_arg(f->args, char *);
+		r = nil;
+	}
+	if(!s && !r)
+		return _fmtcpy(f, "<nil>", 5, 5);
+
+	if(f->flush)
+		outlen = 0x7FFFFFFF;	/* if we can flush, no output limit */
+	else if(f->runes)
+		outlen = (Rune*)f->stop - (Rune*)f->to;
+	else
+		outlen = (char*)f->stop - (char*)f->to;
+
+	_quotesetup(s, r, -1, outlen, &q, f->flags&FmtSharp, f->runes);
+//print("bytes in %d bytes out %d runes in %d runesout %d\n", q.nbytesin, q.nbytesout, q.nrunesin, q.nrunesout);
+
+	if(runesin){
+		if(!q.quoted)
+			return _fmtrcpy(f, r, q.nrunesin);
+		return qstrfmt(nil, r, &q, f);
+	}
+
+	if(!q.quoted)
+		return _fmtcpy(f, s, q.nrunesin, q.nbytesin);
+	return qstrfmt(s, nil, &q, f);
+}
+
+int
+quotestrfmt(Fmt *f)
+{
+	return _quotestrfmt(0, f);
+}
+
+int
+quoterunestrfmt(Fmt *f)
+{
+	return _quotestrfmt(1, f);
+}
+
+void
+quotefmtinstall(void)
+{
+	fmtinstall('q', quotestrfmt);
+	fmtinstall('Q', quoterunestrfmt);
+}
+
+int
+_needsquotes(char *s, int *quotelenp)
+{
+	Quoteinfo q;
+
+	_quotesetup(s, nil, -1, 0x7FFFFFFF, &q, 0, 0);
+	*quotelenp = q.nbytesout;
+
+	return q.quoted;
+}
+
+int
+_runeneedsquotes(Rune *r, int *quotelenp)
+{
+	Quoteinfo q;
+
+	_quotesetup(nil, r, -1, 0x7FFFFFFF, &q, 0, 0);
+	*quotelenp = q.nrunesout;
+
+	return q.quoted;
+}